1. Field of the Invention
This invention relates to a semiconductor device having a package which has therein a semiconductor chip, such as an integrated circuit (IC) or a large scale integrated circuit (LSI) which is connected to a plurality of lead terminals by means of wires. The present invention, in particular, relates to an improved arrangement of the connection of the lead terminals and the semiconductor chip.
2. Description of the Prior Art
In conventional semiconductor devices, the semiconductor chip has bonding pads to which the lead terminals are connected and which are usually located in the vicinity of the peripheral edges of the chip for the purpose of decreasing the length of the wires. If the connecting wires have a large length, they tend to hang down between the bonding pads and the lead terminals, resulting in so-called wire flow. This wire flow causes the wires to accidentally come into contact with a base of the package which supports the lead terminals, resulting in an increased possibility of breakage of the wires. This is particularly a problem when the semiconductor device is used in a vehicle such as an automobile, which is subject to vibration or impact. Therefore, a decrease in the length of the connecting wires is very important.
On the other hand, larger semiconductor chips are now required, to increase the packaging density thereof, yet smaller packages are required to decrease the size of the semiconductor device itself.
The base of the package for carrying the semiconductor chip has a peripheral edge adapted to support the terminal ends of the lead terminals (referred to as a margin area hereinafter). In order to make the package itself small and to enable a large semiconductor chip to be received in the package, the width of the margin area must be as small as possible.
Semiconductor devices of a conventional nature cannot fully satisfy the above-mentioned requirements.